Process for preparing purified alkali metal salts of 4-sulfophenyl-[(1-oxyalkanoyl)amino]alkanoate without isolation of intermediates
US5466840A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 22, 1994 |
| Grant date | Nov 14, 1995 |
| Priority date | — |
| Expiry date | Aug 22, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C303/32
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
This invention relates to a 5 step process for preparing a purified alkali metal salt of 4-sulfophenyl-[(1-oxyalkanoyl)amino]alkanoate in one reaction vessel without isolation of intermediates. The steps are as follows: A) reacting an alkali metal salt of 4-hydroxybenzenesulfonic acid with a C.sub.2 to C.sub.4 carboxylic anhydride in a solvent to form an alkali metal salt of 4-acyloxybenzenesulfonic acid and a C.sub.2 to C.sub.4 carboxylic acid. B) adding an [(1-oxyalkanoyl)amino]alkanoic acid and a transesterification catalyst to the reaction product of step A) and heating at a temperature and pressure sufficient to maintain reflux of the solvent and to remove the C.sub.2 to C.sub.4 carboxylic acid from the reaction vessel to form a reaction mixture containing an alkali metal salt of 4-sulfophenyl-[(1-oxyalkanoyl)amino]alkanoate. C) removing the solvent from the reaction mixture formed in step B). D) mixing the alkali metal salt of 4-sulfophenyl-[(1-oxyalkanoyl)amino]alkanoate product of step C) with acetic acid. E) and finally separating the product from the acetic acid. The purified alkali metal salt of 4-sulfophenyl-[(1-oxyalkanoyl)amino]alkanoate product is useful as a bleach …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.